1. Field
The present invention relates generally to computer-based communication systems.
2. Background
Nodes such as server platforms, client stations, peer stations, and intermediate station nodes in current communication systems typically must select a single channel or single link or other communication interface incident to undertaking a data transfer transaction or a so-called “use case” (essentially, one or more transactions or constituent use cases directed to a common goal), such as the wireless transmission of multimedia data or the downloading of a Web page. This is so even though the nodes themselves might be capable of communicating over a number of diverse channels or links. Service is typically provided over the single channel or link from a single server.
A service provider, either as server or peer, serving a group of clients or peers with multi-channel/multi-link capabilities establishes connections, assigns resources, and otherwise engages in utilizing finite capacities to serve those clients or peers on an “as come” basis. Such allocation often causes ineffective and/or inefficient use of the overall system resources and capabilities as clients or peers engage and disengage services stochastically. For example, a multicast router allocates link utilization based on the shortest route as multicast members engage in a multicast from various point on the global Internet. As time progresses, the router may experience increasing queuing delay on one or more links, while other available links have available capacity to be used.
Currently, this problem is addressed using what can be thought of as the law of large numbers, which entails reliance on low probability events consuming no more than, say, 5% of the total service time wherein the ineffective/inefficient utilization is of significant impact to overall system performance. Such approaches take advantage of the large number of independent arrivals and departures of service requests relative to the capacity of the single resource being used. For example, backbone routers may handle 105 connections at any moment in time on a single link. These connections are engaged and disengaged at a rate of 100 per second, and last on the order of 10 seconds each, leaving sufficient room for the law of large numbers to provide a comfortable margin.
In the case of providing many types of newer services, however, the present invention recognizes that the above-discussed “law of large numbers” can break down. For instance, providing several wireless client stations with multimedia content typically requires high bandwidth since a great deal of data transmission is entailed, and moreover clients typically remain connected for a substantial period, instead of connecting and disconnecting relatively rapidly as is the case for an ordinary telephone call. Unfortunately the server, a wireless communication system base station in this case, has finite transmission bandwidth. It might be able to provide all client stations within its geographic area with a base level of service, e.g., the base station might have the bandwidth to supply all nearby client stations with the base layer of a multimedia stream, but it might not have sufficient bandwidth, depending on the circumstances, to provide all client stations with enhancement layers of the stream. An adjacent base station might happen to have spare bandwidth at that moment, but even if some of the client devices are close enough to it to receive data from the adjacent base station, present protocols permit only the transfer of the entire service between base stations. They do not permit load sharing among base stations to deliver different parts of the same service simultaneously. Having made these critical observations, the invention disclosed herein is provided.